<template>
    <div>
        <router-link
            to="/"
            tag="div"
            class="header-abs"
            v-show="absShow"
        >
            <div class="iconfont header-abs-back">&#xe624;</div>
        </router-link>
        <div class="header-fixed" v-show="!absShow" :style="opcityStyle">
            景点详情
            <router-link to="/">
                <div class="iconfont header-fixed-back">&#xe624;</div>
            </router-link>
        </div>
    </div>
</template>

<script>
    export default {
        name: "DetailHeader",
        data (){
            return{
                absShow:true,
                opcityStyle:{
                    opacity:0
                }
            }
        },
        methods:{
          handleScroll (){
              const top = document.documentElement.scrollTop;
              if(top > 60){
                  let opacity = top / 140
                  opacity = opacity > 1 ? 1 : opacity
                  this.opcityStyle = { opacity }
                  this.absShow = false
              }else{
                  this.absShow = true
              }
          }
        },
        activated (){
            window.addEventListener('scroll',this.handleScroll)
        },
        deactivated (){
            window.removeEventListener('scroll',this.handleScroll)
        }
    }
</script>

<style lang="stylus" scoped>
    @import "~styles/varibles.styl"
    .header-abs
        position:absolute
        left: .2rem
        top: .2rem
        width: .8rem
        height: .8rem
        line-height: .8rem
        text-align center
        border-radius:50%
        background:rgba(0,0,0,.6)
        .header-abs-back
            color: #fff
            font-size: .4rem
    .header-fixed
        z-index:2
        position:fixed
        left: 0
        right: 0
        top: 0
        height:$headerHeight
        line-height:$headerHeight
        text-align:center
        color: #fff
        background:$bgColor
        font-size:.32rem
        .header-fixed-back
            position:absolute
            top:0
            left: 0
            width:.64rem
            text-align:center
            font-size:.4rem
            color: #fff

</style>